Subject: [MEXT] Adoption of draft-droms-mext-nemo-pd-00.txt?

From: marcelo bagnulo braun <[email-masked]>
Date: Fri, 30 May 2008 16:51:28 +0200

Hi,

We would like to ask the WG what is their opinion about accepting 
draft-droms-mext-nemo-pd-00.txt as the WG document for the Nemo PD 
deliverable included in our charter.

Please provide comments so we cna make some progress on this long 
overdue deliverable

thanks, Julien and marcelo
 
-------- Mensaje original --------
Asunto: 	I-D Action:draft-droms-mext-nemo-pd-00.txt
Fecha: 	Fri, 30 May 2008 05:45:01 -0700 (PDT)
De: 	[email-masked]
Responder a: 	[email-masked]
Para: 	[email-masked]

A New Internet-Draft is available from the on-line Internet-Drafts directories.

	Title           : DHCPv6 Prefix Delegation for NEMO
	Author(s)       : R. Droms, et al.
	Filename        : draft-droms-mext-nemo-pd-00.txt
	Pages           : 12
	Date            : 2008-05-30

One aspect of network mobility support is the assignment of a prefix
or prefixes to a Mobile Router (MR) for use on the links in the
Mobile Network.  DHCPv6 prefix delegation can be used for this
configuration task.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-droms-mext-nemo-pd-00.txt

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ftp://ftp.ietf.org/internet-drafts/

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From: Vijay Devarapalli <[email-masked]>
Date: Fri, 30 May 2008 11:18:09 -0700

> Please provide comments so we cna make some progress on this long

I think we should adopt the document as a WG document. We need a mechanism
for delivering the mobile network prefix information dynamically to the
mobile router. The only mechanism that we have today in RFC 3963 is manual
configuration of the prefixes on the mobile router.

Vijay

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From: "George Tsirtsis" <[email-masked]>
Date: Fri, 30 May 2008 21:22:50 +0100

I fully agree, we should adopt this document.

Thanks
George

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From: [email-masked] (Arnaud Ebalard)
Date: Fri, 30 May 2008 22:38:17 +0200

Hi,

> Please provide comments so we cna make some progress on this long

The document is short and easy to read (good point). On one side, I
think that DHCPv6 makes some sense for Nemo PD for devices with some
capabilities. On the other side, I wonder if it is not overkill
(complexity, roundtrips, ...) for a use in small devices (phone?, PDA?)
that will serve a single subnet with IPv6 stateless @ autoconf 

In practice (as a HA and MR administrator), I'd like to be able to
simply configure the prefixes for my MR in the HA configuration section
for this MR and that those prefixes be sent to the MR during the
initial binding if it ask for prefix(es). In a sense considering the
an initial static configuration of a MR, switching to PD would mean:

  - changing a knob in the MR config to switch to prefix delegation
  - giving the prefix in the HA config, indicating PD for that MR

i.e. no need for IDs, specific keys for auth, or additional relay and
associated IPsec credentials config.

I also have some comments on the "Security Considerations" section of
the document. Don't hesitate to tell me if I missed sth or if it is out
of scope.

IMHO, this is a bit simplistic to delegate the security of NEMO PD to
the Security Considerations sections of DHCPv6 and DHCPv6 PD documents.
There are good chances that the environments where MR will operate may
be a bit more hostile than those where more common routers are expected
to operate (in operators or corporate networks). 

Some initial thoughts:

- What are the hypothesis behind 3315 and 3633 design decisions that do
  not hold anymore in MIPv6 environments (if any)?
- "HAs and MRs SHOULD use DHCPv6 authentication": Why not a "MUST"?
- how do the security mechanisms of both protocols interact?
- In the simple mode (no relay), how will the use of multicast interact
  with IPsec protection of traffic if it is in place?
- HMAC-MD5-based authentication method is the only one defined in
  3315. Is it sufficient?
- What is the impact of the assignment of new prefixes in a dynamic
  fashion w.r.t. the SPD and SADB or IKE daemons? How should that be
  handled.
- ...

Regards,

a+

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From: marcelo bagnulo braun <[email-masked]>
Date: Fri, 30 May 2008 23:45:08 +0200

Hi Arnaud,

thanks for the feedback

> associated IPsec credentials config.
I am not sure what you mean hre. Are you suggesting any additional 
changes in the document? Or are you proposing using a different 
mechanism other than dhcp for this?

If it is the first one, please comment how to do this.

If it is the second one, there is consensus in the WG (decided in the 
last meeting and confirmed in the ml) that we are using dhcp for this, 
so pleas do not go into this disucssion again

>   fashion w.r.t. the SPD and SADB or IKE daemons? How should that be
This should be discussed, since the security was one of the points that 
needed more work and that the authors tried to address in thei document

Regards, marcelo

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From: [email-masked] (Arnaud Ebalard)
Date: Sat, 31 May 2008 01:47:20 +0200

Hi Marcelo,

marcelo bagnulo braun <[email-masked]> writes:

> changes in the document?

Not in that part of my first reply.

> Or are you proposing using a different  mechanism other than dhcp for
> this?

No, I do not propose another mechanism. I just give my feedback on the
pros and cons of the proposal in term of coverage. To make it clear, I
think that the proposal will cover the needs of big infrastructures. As
it is probably a part of the audience, I think the document deserves to
be a Working Group item. 

That been said, it's not because I consider that the document deserves
to be WG item for that part of the audience that I think it will provide
a "one size fits all" solution for NEMO PD, for instance for very small
devices like PDA or Phones. I was basically wondering if I will ever
have to install and configure a DHCPv6 server with Relay and PD support
on my Phone or PDA just for the purpose of getting a prefix from my
HA. But considering what you write below (hiring DHCP for the job is
the consensus), this will be the case. 

> so pleas do not go into this disucssion again

ok. Sorry for the noise, then. Just keep my comments w.r.t. the Security
Considerations section. 

Regards,

a+

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From: "George Tsirtsis" <[email-masked]>
Date: Sun, 1 Jun 2008 08:50:56 +0100

> the consensus), this will be the case.

Arnaud,

This maybe simply a misunderstanding but draft-droms does not require
you to do this. The Mobile Router, is a Requesting Router (RR) i.e., a
DHCP-PD client. So no server functionality is required in you small
devices.

George